Plain form is useful when you want quickly to create a form, for which you do not need separate Form class. It basicallly instantiates Kris\LaravelFormBuilder\Form class. It’s same as creating regular form, only the first parameter is skipped.

<?php
$formOptions = [
    'url' => route('password.reset'),
    'method' => 'POST'
];

$form = \FormBuilder::plain($formOptions)->add('email', 'email', [
    'label' => 'Email address'
]);

Or if you use the FormBuilderTrait in controller:

<?php

use Kris\LaravelFormBuilder\FormBuilderTrait;

class UserController extends Controller {

    use FormBuilderTrait;

    public function userPage()
    {
        $form = $this->plain($formOptions)->add('email', 'email', [
            'label' => 'Email address'
        ]);

        return view('user', compact('form'));
    }
}